Low-speed diesel engines are basically used on large ships.

Because this diesel engine has a relatively low speed (torque is larger than other diesel engines), the fuel consumption is relatively large.

In addition to military applications, such as internal combustion engine aircraft carriers, warships and submarines, some tanks are also used, but different from the marine but also low-speed diesel engines.

The diesel engine has high thermal efficiency, good economy, easy starting, and great adaptability to various types of ships. It was soon used as a propulsion power for ships. By the 1950s, diesel engines almost completely replaced steam engines in newly built ships. Marine diesel engines are the main driving force for civilian ships, small and medium-sized ships and conventional submarines .